C# in a Nutshell

Predefined Types

This section explains each of C#’s predefined types:

• Value types

  • Integer, signed (sbyte, short, int, long)

  • Integer, unsigned (byte, ushort, uint, ulong)

  • Floating-point (float, decimal, char, bool)

• Reference types

  • Object

  • String

All of these types alias types found in the System namespace. For example, there is only a syntactic difference between these two statements:

int i = 5;
System.Int32 i = 5;

Integral Types

This table lists the integral types and their features:

C# type	System type	Size	Signed
sbyte	System.SByte	1 byte	yes
short	System.Int16	2 bytes	yes
int	System.Int32	4 bytes	yes
long	System.Int64	8 bytes	yes
byte	System.Byte	1 byte	no
ushort	System.UInt16	2 bytes	no
uint	System.UInt32	4 bytes	no
ulong	System.UInt64	8 bytes	no

For unsigned integers that are n bits wide, possible values range from 0 to 2. For signed integers that are n bits wide, their possible values range from -2 ^n-1 to 2 ^n-1-1. Integer literals can use either decimal or hexadecimal notation:

int x = 5;
ulong y = 0x1234AF; // prefix with 0x for hexadecimal

When an integral literal is valid for several possible integral types, the default type chosen goes in this order: int, uint, long, and ulong. The following suffixes may be used to explicitly specify the chosen type:

U

uint or ulong

L

long or ulong

UL

ulong

Integral conversions

An implicit conversion between integral types is permitted when the type to convert to contains every possible ...